1. Field of the Invention
The present invention relates to a pump transferring a fluid and, more particularly, to a thermal actuation pump using a thermoelectric element.
2. Description of the Related Art
Rapid progression of a micro-machining technology has resulted in the development of various functions of a micro electro mechanical system (MEMS). The MEMS has many advantages in view of size, cost and reliability. Therefore, the MEMS has been developed for wide fields of application.
In particular, there have been many studies in progress for integrating a fluid system and embodying the integrated fluid system on single chip. A micro pump is a major element of the integrated fluid system for transferring a working fluid.
A thermal actuation pump has been used as the micro pump. Conventionally, the thermal actuation pump includes a chamber with an inlet and an outlet, and a heating unit such as a heater for heating the chamber. For operating the thermal actuation pump, electric power is supplied to the heating unit. The chamber is heated by the heating unit and a gas in the chamber is expanded. Accordingly, an inside pressure of the chamber increases and the gas in the chamber flows out through the outlet. On the contrary, if the gas in the chamber is contracted by cooling the heating unit, the inside pressure of the chamber decreases. Accordingly, external gas flows in the chamber through the inlet.
As mentioned above, the conventional thermal actuation pump requires an additional cooling device such as a heat sink for cooling the heated heating unit. However, it is a very complicated process to implement the cooling device in the integrated pump. Also, the structure of the integrated pump becomes complex. Furthermore, the heat generated from the heating unit cannot be re-used since the heat sink must cool the generated heat for decreasing the inside pressure of the chamber. Therefore, the conventional thermal actuation pump consumes a comparatively large amount of energy for heating and cooling the heating unit.